/* Layout : une colonne de lecture (~68ch), démos et code peuvent s'élargir un peu. Barre de navigation fine en haut. */
@import url("https://fonts.googleapis.com/css2?family=Unbounded:wght@500;700&family=IBM+Plex+Sans:ital,wght@0,400;0,600;1,400&family=JetBrains+Mono:wght@400;600&display=swap");

:root {
  --bg: #f5f6f9;
  --surface: #ffffff;
  --sunken: #eceef4;
  --fg: #171a24;
  --muted: #5b6275;
  --line: #d8dce6;
  --accent: #c8431a;      /* orange "sommet" : titres, repères */
  --link: #1d5fa8;        /* bleu : liens, code */
  --ok: #2b7a3d;
  --warn: #9a6400;
  --code-bg: #1b1f2a;
  --code-fg: #e4e7ef;
  --code-kw: #ff9e64;
  --code-ty: #7dcfff;
  --code-str: #b5e08a;
  --code-num: #f7c86b;
  --code-com: #8189a3;
  --font-display: "Unbounded", "Trebuchet MS", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "Cascadia Code", Consolas, monospace;
  --measure: 70ch;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #11141b; --surface: #181c25; --sunken: #1f2430; --fg: #e5e8ef; --muted: #9aa2b6;
    --line: #2e3442; --accent: #ff7d4a; --link: #7ab8ff; --ok: #6cc77f; --warn: #e3b14d;
    --code-bg: #0b0d12; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #11141b; --surface: #181c25; --sunken: #1f2430; --fg: #e5e8ef; --muted: #9aa2b6;
  --line: #2e3442; --accent: #ff7d4a; --link: #7ab8ff; --ok: #6cc77f; --warn: #e3b14d;
  --code-bg: #0b0d12; color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 400 17px/1.65 var(--font-body);
}
a { color: var(--link); text-underline-offset: 3px; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}

/* Barre du haut */
.topbar {
  border-bottom: 1px solid var(--line); background: var(--surface);
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}
.topbar-in {
  max-width: 980px; margin: 0 auto; display: flex; flex-wrap: wrap; gap: 8px 20px;
  align-items: center; justify-content: space-between; padding-block: 10px;
  font-size: 14px;
}
.brand { font-family: var(--font-display); font-weight: 700; font-size: 14px; color: var(--fg); text-decoration: none; letter-spacing: .01em; }
.brand span { color: var(--accent); }
.topnav { display: flex; flex-wrap: wrap; gap: 4px 14px; }
.topnav a { color: var(--muted); text-decoration: none; }
.topnav a:hover, .topnav a[aria-current="page"] { color: var(--fg); text-decoration: underline; }

main {
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: 32px 80px;
}
.page { max-width: var(--measure); margin: 0 auto; }
.wide { max-width: 900px; margin-left: auto; margin-right: auto; }

/* Titres */
.eyebrow {
  font: 600 12.5px/1.2 var(--font-mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent); margin: 0 0 10px;
}
h1, h2, h3 { text-wrap: balance; line-height: 1.2; }
h1 { font-family: var(--font-display); font-weight: 700; font-size: clamp(28px, 5vw, 40px); margin: 0 0 14px; letter-spacing: -0.01em; }
h2 { font-family: var(--font-display); font-weight: 500; font-size: clamp(21px, 3.2vw, 26px); margin: 56px 0 12px; padding-top: 18px; border-top: 1px solid var(--line); }
h3 { font-size: 19px; font-weight: 600; margin: 32px 0 8px; }
.lede { font-size: 19px; color: var(--muted); margin: 0 0 20px; }
p, ul, ol { margin: 0 0 14px; }
li { margin: 4px 0; }
strong { font-weight: 600; }

/* Fiche de séance */
.meta { display: flex; flex-wrap: wrap; gap: 6px 22px; font-size: 14.5px; color: var(--muted); margin: 0 0 8px; }
.meta b { color: var(--fg); font-weight: 600; }
.objectifs { background: var(--surface); border: 1px solid var(--line); border-radius: 6px; padding: 14px 18px; margin: 20px 0; }
.objectifs h3 { margin: 0 0 6px; font-size: 15px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.objectifs ul { margin: 0; padding-left: 20px; }
.toc { font-size: 15px; }
.toc ol { padding-left: 22px; }

/* Code */
code { font-family: var(--font-mono); font-size: .88em; background: var(--sunken); padding: 1px 5px; border-radius: 4px; }
pre {
  position: relative; background: var(--code-bg); color: var(--code-fg); border-radius: 6px;
  padding: 14px 16px; overflow-x: auto; font: 400 14px/1.55 var(--font-mono); margin: 0 0 18px;
  tab-size: 2;
}
pre code { background: none; padding: 0; font-size: inherit; color: inherit; }
pre[data-file]::before {
  content: attr(data-file); display: block; font-size: 12px; color: var(--code-com);
  margin: -4px 0 8px; letter-spacing: .03em;
}
.tok-kw { color: var(--code-kw); }
.tok-ty { color: var(--code-ty); }
.tok-str { color: var(--code-str); }
.tok-num { color: var(--code-num); }
.tok-com { color: var(--code-com); font-style: italic; }
.tok-todo { color: #1b1f2a; background: var(--code-num); font-style: normal; border-radius: 3px; padding: 0 3px; }
.copy-btn {
  position: absolute; top: 8px; right: 8px; font: 500 12px var(--font-body); color: var(--code-fg);
  background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.18); border-radius: 4px;
  padding: 3px 8px; cursor: pointer; opacity: .75;
}
.copy-btn:hover { opacity: 1; }

/* Encadrés : étiquette + fond léger */
.box { border-radius: 6px; padding: 12px 16px 2px; margin: 20px 0; background: var(--surface); border: 1px solid var(--line); }
.box > .box-label { display: block; font: 600 12px/1 var(--font-mono); letter-spacing: .08em; text-transform: uppercase; margin-bottom: 8px; }
.box.retenir { border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); }
.box.retenir > .box-label { color: var(--accent); }
.box.attention > .box-label { color: var(--warn); }
.box.attention { border-color: color-mix(in srgb, var(--warn) 45%, var(--line)); }
.box.question > .box-label { color: var(--link); }
.box.plus > .box-label { color: var(--muted); }
.box.verif { border-color: color-mix(in srgb, var(--ok) 45%, var(--line)); }
.box.verif > .box-label { color: var(--ok); }

/* Tableaux */
.table-wrap { overflow-x: auto; margin: 0 0 18px; }
table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-weight: 600; color: var(--muted); font-size: 13.5px; text-transform: uppercase; letter-spacing: .04em; }

/* Démos */
.demo { margin: 26px -8px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.demo-head { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; padding: 10px 14px; border-bottom: 1px solid var(--line); font-size: 14px; }
.demo-head b { font-family: var(--font-mono); font-size: 12px; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); }
.demo-body { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 0; }
.demo-body.single { grid-template-columns: minmax(0, 1fr); }
.demo canvas { display: block; width: 100%; aspect-ratio: 1 / 1; max-width: 100%; background: #0d1017; touch-action: none; }
.demo canvas.wide-canvas { aspect-ratio: 16 / 9; }
.demo-controls { padding: 14px; display: flex; flex-direction: column; gap: 12px; font-size: 14.5px; min-width: 0; border-left: 1px solid var(--line); }
.demo-controls label { display: flex; flex-direction: column; gap: 3px; }
.demo-controls .row { display: flex; flex-wrap: wrap; gap: 8px 14px; align-items: center; }
.demo-controls .row label { flex-direction: row; align-items: center; gap: 6px; }
.demo-controls output, .demo-readout { font-family: var(--font-mono); font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.demo-readout { white-space: pre; overflow-x: auto; background: var(--sunken); padding: 8px 10px; border-radius: 4px; color: var(--fg); }
.demo-caption { padding: 10px 14px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.demo input[type="range"] { width: 100%; accent-color: var(--accent); }
.demo textarea { width: 100%; min-height: 170px; font: 13px/1.5 var(--font-mono); background: var(--code-bg); color: var(--code-fg); border: 0; border-radius: 4px; padding: 10px; resize: vertical; }
.btn { font: 500 14px var(--font-body); color: var(--fg); background: var(--sunken); border: 1px solid var(--line); border-radius: 5px; padding: 6px 12px; cursor: pointer; }
.btn:hover { border-color: var(--muted); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
a.btn { display: inline-block; text-decoration: none; }
.telechargement { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; margin: 18px 0; }
.telechargement .btn { font-size: 15px; padding: 8px 16px; }
.telechargement span { font-size: 14px; color: var(--muted); }
.err { color: #e5484d; font-family: var(--font-mono); font-size: 12.5px; white-space: pre-wrap; }
@media (max-width: 720px) {
  .demo { margin-left: 0; margin-right: 0; }
  .demo-body { grid-template-columns: minmax(0, 1fr); }
  .demo-controls { border-left: 0; border-top: 1px solid var(--line); }
}

/* Schémas SVG */
figure { margin: 24px 0; }
figure svg { display: block; width: 100%; height: auto; }
figcaption { font-size: 14px; color: var(--muted); margin-top: 8px; }
.diagram { overflow-x: auto; }
.svg-fg { fill: var(--fg); }
.svg-muted { fill: var(--muted); }
.svg-line { stroke: var(--line); }
.svg-stroke { stroke: var(--fg); }

/* Matrices écrites en HTML */
.math { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin: 14px 0 18px; font-family: var(--font-mono); font-size: 15px; overflow-x: auto; }
.mat { display: inline-grid; gap: 2px 14px; padding: 4px 10px; border-left: 2px solid var(--fg); border-right: 2px solid var(--fg); border-radius: 6px; text-align: center; }
.mat.c1 { grid-template-columns: auto; }
.mat.c2 { grid-template-columns: repeat(2, auto); }
.mat.c3 { grid-template-columns: repeat(3, auto); }
.mat.c4 { grid-template-columns: repeat(4, auto); }
.mat .hl { color: var(--accent); font-weight: 600; }

/* Étapes de TP */
.etape { counter-increment: etape; }
.etape > h2::before { content: "Étape " counter(etape) " · "; color: var(--accent); }
.page.tp { counter-reset: etape; }
.page.tp.zero { counter-reset: etape -1; }
.todo-list { list-style: none; padding-left: 0; }
.todo-list li { padding-left: 26px; position: relative; }
.todo-list li::before { content: ""; position: absolute; left: 2px; top: .45em; width: 12px; height: 12px; border: 1.5px solid var(--muted); border-radius: 3px; }
details { background: var(--surface); border: 1px solid var(--line); border-radius: 6px; padding: 10px 14px; margin: 14px 0; }
details summary { cursor: pointer; font-weight: 600; }
details[open] summary { margin-bottom: 10px; }
.files { font-family: var(--font-mono); font-size: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: 6px; padding: 12px 16px; white-space: pre; overflow-x: auto; line-height: 1.6; }

/* Sommaire (accueil) */
.seances { list-style: none; padding: 0; margin: 24px 0; display: grid; gap: 0; border-top: 1px solid var(--line); }
.seances li { margin: 0; display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 4px 18px; padding: 20px 0; border-bottom: 1px solid var(--line); }
.seances .num { font-family: var(--font-display); font-weight: 700; font-size: 30px; color: var(--accent); line-height: 1; }
.seances h3 { margin: 0 0 4px; font-size: 20px; }
.seances p { margin: 0 0 8px; color: var(--muted); font-size: 15.5px; }
.seances .links { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 15px; }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 56px; padding-top: 16px; border-top: 1px solid var(--line); font-size: 15px; flex-wrap: wrap; }

@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; } }